摘要
采用Ansys建立128 m新型大跨铁路应急钢桁梁的计算模型,系统分析不同工况和非线性因素作用下的结构稳定性,探讨列车荷载、风荷载、温度、初始缺陷、几何非线性和材料非线性等因素对结构稳定性的影响。结果表明:不同荷载组合形式和分布形式下,结构稳定系数和失稳模态不同,主力作用下最低线弹性稳定系数为8.093,失稳形式为局部竖向失稳;随着横向风荷载的增大,结构稳定系数逐渐下降,且失稳模态由竖向失稳变为横向失稳;温度变化对大跨简支钢桁梁的稳定性影响很小;考虑初始缺陷时,稳定系数随初始缺陷的增大而减小,竖向失稳模态对竖向偏位较敏感,而横向失稳对横向偏位较敏感;考虑材料非线性因素时,相比线弹性稳定分析,稳定系数降低约70%,远远高于几何非线性对稳定性的影响,稳定分析中必须考虑材料非线性的影响;综合考虑各种因素,大跨应急钢桁梁最不利稳定系数为1.925,结构稳定性良好。
Based on Ansys,the calculation model of 128 m new long-span railway emergency steel truss girder was established.A systematical analysis of structural stability was carried out under different conditions and nonlinear factors to study the influence of train load,wind load,temperature,initial deviation,geometric nonlinearity and material nonlinearity on the structural stability.The results show that the structural stability coefficients and instability modes are different when the combination and distribution form of loads are different.Under the main force,the lowest linear elastic stability coefficient is 8.093,with the local vertical instability as the instability mode.As the lateral wind load increases,the structural stability coefficient decreases gradually with the instability mode changing from vertical instability to transverse instability.The temperature has a minor influence on the long-span steel truss girder.When the initial deviation is considered,the stability coefficient decreases with the increase of the initial deviation.The vertical instability is more sensitive to the vertical deviation,while the transverse instability is more sensitive to the transverse deviation.When the material nonlinearity is considered,compared with linear elastic stability analysis,the stability coefficient decreases about 70%,which is much higher than the influence of geometric nonlinearity on stability.The influence of material nonlinearity must be considered during stability analysis.With comprehensive consideration of all the factors,the most unfavorable stability coefficient is 1.925,showing good stability of the steel truss girder.
作者
赵曼
陈士通
孙志星
许宏伟
黄晓明
ZHAO Man;CHEN Shitong;SUN Zhixing;XU Hongwei;HUANG Xiaoming(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Hebei Engineering Research Center for Traffic Emergency and Guarantee,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Transportation,Southeast University,Nanjing 210096,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第1期119-127,共9页
Journal of the China Railway Society
基金
国家重点研发计划(2021YFB2600605,2021YFB2600601,2021YFB2600600)
河北省高等学校科学技术研究项目(QN2017357)。
关键词
铁路
钢桁梁
稳定性
线弹性
非线性
初始缺陷
railway
steel truss girder
stability
linear elasticity
nonlinearity
initial deviation
